perilous

The story

1. Latin · derived fromperīculōsus
2. Old French · derived fromperilleus
3. Middle English · inherited fromperilous
4. English todayperilous

From Middle English perilous, from Old French perilleus, equivalent to peril + -ous, from the noun peril, or from Latin perīculōsus. Doublet of periculous.

Words from the same roots